KR20110041951A - Organic electron donor materials based on organic material for organic solar cell and the production method thereof - Google Patents

Abstract

PURPOSE: A compound as an electron donor material of an organic solar cell is provided to produce an organic solar cell of low molecular level. CONSTITUTION: A 2,5-bis[4-(N,N-diphenylamino) styryl]thiophene compound as a electron donor material of an organic solar cell is denoted by chemical formula 1 or 2. The electron donor material is prepared by reacting 2,5-dibromothiophene or 5,5'-dibromo-2,2'-bithiophene, Biphenyl-(4-vinylphenyl)amine, Palladium acetate, tetrabutylammonium bromide, and NaOAC. The compound is thermally stable. PCBM[[6,6]-phenyl-C61-butyric acid methyl ester] is mixed to the electron donor material as a receptor.

Description

Organic electron donor materials based on organic material for organic solar cell and the production method

The present invention relates to a compound which acts as an electron donor material of an organic solar cell, a method for preparing the compound and an organic solar cell using the compound, and more particularly, to 2,5 which acts as an electron donor material of an organic solar cell. -bis [4- (N, N-diphenylamino) styryl] thiophene or 2,5-bis [4- (N, N-diphenyl amino) styryl] -2,2-bithiophene compound, method for preparing the compound and high hole A thiophene derivative having a hole movement speed is the center, and a compound conjugated with two or more triphenylamine derivatives outside the thiophene derivative is used as an electron donor material. It relates to an organic solar cell.

Since the invention of Dr. Tang's organic solar cell in Kodak in 1986, researches on various organic solar cells have been carried out by researchers around the world. Organic solar cells have been developed by various inventors because of their low cost and easy fabrication of devices, but they have disadvantages of low efficiency. Therefore, although many inventors have conducted various studies to increase the efficiency using low molecular weight materials in organic solar cells, they still have the disadvantage of low efficiency.

In general, recent studies on organic solar cells have begun to introduce compounds with fast hole transport rates, such as thiophenes and asens, into solar cells. However, these materials have the disadvantage of standing vertically on ITO substrates, which are often used for organic transistors, but are not efficient for organic solar cells. In recent years, the Roncali group has introduced triphenylamine derivatives into organic solar cell devices to make devices more efficient. Triphenylamine has recently been studied as a spin coating method because of its ability to absorb light and transfer holes efficiently without standing vertically on a substrate because of its three-dimensional structure.

Accordingly, the present inventors are trying to develop a material that acts as a compound for acting as an electron donor material of an organic solar cell, and has a thiophene derivative and a triphenylamine derivative having a high hole transport rate. The conjugated conjugated compound was developed as an electron donor material, and the present invention was completed by confirming that they can be usefully used in organic solar cell devices.

It is an object of the present invention to provide organic compounds and methods for their preparation that can be usefully used as organic solar cell materials at low molecular levels.

Still another object of the present invention is to provide an organic solar cell using the electron donor material and a method of manufacturing the same.

In order to achieve the above object, the present invention is the following formula 1 (2,5-bis [4- (N, N-diphenylamino) styryl] thiophene) or 2 (2,5) as an electron donor material of an organic solar cell -bis [4- (N, N-diphenylamino) styryl] -2,2-bithiophene).

<Formula 1>

<Formula 2>

In addition, the present invention reacts with 2,5-dibromothiophene or 5,5'-dibromo-2,2'-bithiophene, Biphenyl- (4-vinylphenyl) amine, Palladium acetate, Tetrabutylammonium bromide and NaOAC to act as an electron donor material. It provides a method for preparing the compound.

In addition, the present invention is the center of the thiophene derivative (thiophene) having a high hole movement (thiophene) center, and the two or more triphenylamine derivatives conjugated to the outside of the thiophene derivative to give an electron Provided is an organic solar cell, which is used as a material.

In addition, the present invention provides a method for manufacturing the organic solar cell, characterized in that the spin coating the PCBM acting as an electron acceptor to the electron donor material.

Hereinafter, the present invention will be described in detail.

The present invention is the formula 1 (2,5-bis [4- (N, N-diphenylamino) styryl] thiophene) or 2 (2,5-bis [4- (N) which acts as an electron donor material of an organic solar cell. , N-diphenylamino) styryl] -2,2-bithiophene).

The present invention also reacts with 2,5-dibromothiophene or 5,5'-dibromo-2,2'-bithiophene, Biphenyl- (4-vinylphenyl) amine, Palladium acetate, tetrabutylammonium bromide and NaOAC to act as electron donor materials. It provides a method for preparing the compound.

In the method for producing the compound of the present invention, it is preferable that the compound is prepared by the reaction of Scheme 1 or Scheme 2 below.

<Scheme 1>

<Scheme 2>

In addition, the present invention is the center of the thiophene derivative (thiophene) having a high hole movement (thiophene) center, and the two or more triphenylamine derivatives conjugated to the outside of the thiophene derivative to give an electron Provided is an organic solar cell, which is used as a material.

In the organic solar cell of the present invention, the compound is preferably thermally stable and spin-coated, and the number of the thiophene derivatives, which are the centers, is preferably 1-5.

In addition, in the organic solar cell of the present invention, it is preferable that PCBM ([6,6] -phenyl-C61-butyric acid methyl ester) serving as an electron acceptor is mixed with the electron donor material, wherein the PCBM is the It is preferably contained in an amount of 1 to 4 by weight of the electron donor material, and the combined compound of the triphenylamine derivative and the thiophene derivative is most preferably Formula 1 or Formula 2.

In addition, the present invention provides a method for manufacturing the organic solar cell, characterized in that the spin coating the PCBM acting as an electron acceptor to the electron donor material.

In the method of manufacturing an organic solar cell of the present invention, the formula 1 or 2 and PCBM is preferably a weight ratio of 1: 1 to 1: 4.

The present invention provides novel electron donor materials combining triphenylamine and thiophene derivatives having good hole transport rates, and these extend the absorption of light to the visible range, and thus the low molecular weight It can be usefully used as the level of organic solar cell materials. In addition, by varying the electron donor material and the electron acceptor material (PCBM) in an appropriate ratio up to a weight ratio of 1: 1 to 1: 4, and having a high efficiency, spin coating is possible, an organic solar cell capable of manufacturing a large area solar cell device Provided is a method of manufacturing a battery element. In addition, generally known electron donor materials of organic solar cells have the disadvantage of thermally unstable, but the material of the present invention is thermally stable and spin coating. In addition, the present invention also proposed a method that can be confirmed through the AFM picture that the efficiency difference between the organic solar cells.

A general organic solar cell device has an anode formed on an ITO substrate, and a conductive polymer (PEDOT), an electron donor layer, an electron acceptor layer, an exciton barrier layer, and a cathode are sequentially formed on the anode. Principle of operation When the light is irradiated to the device, excitons are formed in the electron donor layer by the light. The excitons move along the organic layer and move to the electron accepting layer, which moves to the fullerene interface with a very high electron affinity, which results in photoexduced charge transfer between the fullerene and the organic material at the interface. Charge separation occurs at the interface between a pair of holes and electrons. The holes and electrons formed thereafter are respectively moved to the cathode electrode along the fullerene layer having a high electron affinity, and holes (holes) are moved toward the anode, thereby forming a current.

Firstly, the inventors of the present invention conducted the Heck reaction to the above Chemical Formula 1 (2,5-bis [4- (N, N-diphenylamino) styryl] thiophene) (1) and Chemical Formula 2 (2,5-bis [4- (N, N-diphenylamino) styryl] -2,2'-bithiophene) (2) was synthesized. That is, the compound of formula 1 is reacted by heating 2,5-dibromothiophene, Biphenyl- (4-vinylphenyl) amine, Palladium acetate, Tetrabutylammonium bromide, NaOAC in DMF solvent, removing DMF and extracting the reaction with methylene chloride and Washed, dried with MgSO ₄ and separated by column chromatography. (See Example 2-1)

On the other hand, the compound of formula 2 is reacted by heating 5,5'-dibromo-2,2'-bithiophene, Biphenyl- (4-vinylphenyl) amine, Palladium acetate, tetrabutylammonium bromide, NaOAC in DMF solvent and then remove DMF The reaction was extracted with methylene chloride, washed with water, dried with MgSO ₄ and separated by column chromatography. In addition, the compound was confirmed by NMR and molecular weight analysis (see Example 2-2).

The inventors measured absorption and emission spectra in methylene chloride solvent or in a transparent solid film, each of the compounds of Formulas 1 and 2 above, and also in a solution and compound film in which the compounds 1 and 2 were mixed in a 1: 1 ratio. (see Figs. 1 to 4). In particular, in the solid film mixed with No. 1,2 and PCBM in a 1: 1 ratio, the emission spectrum is reduced as electrons move to excitons excited by PCBM molecules (see FIG. 4 ). In order to determine the electrochemical characteristics of the compound No. 2 and the energy band gap of the material, electrochemical analysis was performed (see FIGS . 5 and 6 ). As a result, compounds 1 and 2 both exhibit an electrochemically reversible oxidation process and exhibit stable electrochemical stability when cationic radicals are formed. In addition, the present inventors confirmed that the thermal stability through the TGA analysis of compounds 1 and 2, both thermally stable (see FIGS . 14 and 15 ).

The present inventors fabricated an organic solar cell device by spin coating a PEDOT, a conductive polymer on the ITO substrate, and using compounds 1 and 2 only with an electron donor layer or spin coating PCBM with an electron acceptor layer. .

At this time, the activation layer was configured in two ways. In the case of the first method, in order to see the phenomenon in the absence of PCBM, the device using only the compound 1 and 2 as the electron donor layer was constructed. Here, BPhen was vacuum deposited to form an exciton barrier layer, and aluminum was vacuum deposited to form an electrode to form an organic solar cell device (see FIG. 7 ).

In the second method, the device was constructed by changing the ratio of compound 1 alone or compound 1 and PCBM to 1: 1, 1: 2, 1: 3, 1: 4. As a result, only a single layer of compound 1 was formed. When the efficiency was confirmed that there is little, when the ratio of the compound 1 and the PCBM 1: 3 was the most efficient (see Fig. 8 and Table 1 ).

As a result of changing the ratio of compound 2 alone or compound 2 and PCBM to 1: 1, 1: 2, 1: 3, 1: 4, the device was constructed. It was confirmed that the most efficient when the ratio of compound 2 and PCBM 1: 4 (see Fig. 9 and Table 1 ).

In addition, the inventors of the present invention confirmed the difference between the devices through AFM (atomic force microscopy), and when the compound No. 1 and the PCBM were 1: 1, there were many holes or aggregated surfaces, whereas the film was 1: 3. It could not be confirmed that the surface of was clean and formed into agglomerates or holes (see FIGS . 10 and 11 ). In addition, when the No. 2 compound and PCBM are 1: 1, many holes or agglomerated surfaces are present, whereas when 1: 4, the surface of the film is clean and agglomeration or pores cannot be confirmed ( FIG. 12 and FIG . 12) . 13 ). In case 1, compound 1 and PCBM are the best when the ratio is 1: 3. In case 2, compound 2 and the PCBM are the best when the ratio is 1: 4. I could confirm through the photo.

As described above, the compound of Chemical Formulas 1 and 2 of the present invention is an electron donor material having high efficiency by extending the absorption of light to the visible light region and introducing a material having a good hole transport rate, so that the organic solar cell of low molecular level It can be usefully used for the preparation of.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are only for illustrating the present invention, and the present invention is not limited to the following examples and may be changed to other embodiments equivalent to substitutions and equivalents without departing from the technical spirit of the present invention. Will be apparent to those of ordinary skill in the art.

Example 1 Reagents and Instruments

<1-1> Reagents Used

Tetrabutylammonium bromide (TBAB), N, N-dimethylformamide (DMF), Pd (OAC) ₂ , 2,5-dibromothiophene, 5,5'-dibromo-2,2'-bithiophene, PCBM {(6,6) -phenyl C ₆₁ butyric acid methyl ester} and BPhen (4,7-diphenyl-1,10-phenanthroline) were used by Aldrich. Methylene chloride and hexane used the tablet chemical. NaOAC and MgSO ₄ used Duksan Chemical.

<1-2> compound identification mechanism

All new compounds were structured using ¹ H-NMR and ¹³ C-NMR using Bruker AM-300 MHz and 500 MHz. UV was used on Beckman DU-650 spectra and JASCO FP-7500, a fluorescence spectrometer. In order to measure the electrochemical stability, the electrochemical properties were confirmed by using CH instrument 660, and by using the AFM device of PSIA XE-100 company to check the film structure of the device, and to measure the thickness of the organic layer. The measurement was performed using an Alpha step apparatus, and TGA analysis (DSC deletion) was performed to confirm thermal stability.

Example 2 Synthesis of Substances of Formula 1 and Formula 2

Compounds of Chemical Formulas 1 and 2 according to the present invention were synthesized through a Heck reaction.

<2-1> Synthesis of 2,5-bis [4- (N, N-diphenylamino) styryl] thiophene (1)

The synthesis scheme of the compound of Formula 1 is as follows:

<Scheme 1>

Specifically, 2,5-dibromothiophene 808 mg (3.34 mmol), Biphenyl- (4-vinylphenyl) amine 1.84 g (6.68 mmol), Palladium acetate 33.1 mg (0.204 mmol), tetrabutylammonium bromide 215 mg (0.66 mmol) ), placed into a NaOAC 1.42 g (17.3 m㏖) under 20 ㎖ DMF solvent after after after while heating to 100 ℃ reaction the reaction was completed, remove the DMF and the reaction was extracted with dichloromethane three times and washed with water 3 times, MgSO ₄ After the water was removed, the compound of Chemical Formula 1 was separated by column chromatography. Recrystallization gave a red solid compound in a yield of 33.6% (700 mg).

Wherein the NMR data and molecular weight are as follows:

¹ H-NMR (300 MHz, CDCl ₃ ): δ (ppm) 7.35 (d, J = 9 Hz, 4H), 7.29 (t, J = 15 Hz, 8H), 7.18 (d, J = 6 Hz, 4H ) 7.06 (t, J = 9 Hz, 4H), 7.01 (d, J = 9 Hz, 4H), 6.92 (s, 2H), 6.87 (s, 2H). ¹³ C NMR (125 MHz, CDCl ₃ ): δ (ppm) 147.5, 142.3, 131.2, 129.4, 127.9, 127.6, 127.3, 126.7, 125.6, 124.6, 123.9, 120.4.

Molecular weight: ^Calcd for C ₄₄ H ₃₄ N ₂ S [M] ⁺ 622.2443, HR-Mass Data: 622.2444.

<2-2> Synthesis of 2,5-bis [4- (N, N-diphenylamino) styryl] -2,2'-bithiophene (2)

The synthesis scheme of the compound of formula 2 is as follows:

<Scheme 2>

5,5'-dibromo-2,2'-bithiophene 835 mg (2.57 mmol), Biphenyl- (4-vinyl phenyl) amine 1.40 g (5.15 mmol), Palladium acetate 25.5 mg (0.15 mmol), tetrabutylammonium bromide 165 mg (0.51 mmol) and 1.09 g (13.3 mmol) of NaOAC were added under 20 ml of DMF solvent and the reaction was carried out while heating to 100 ° C. After completion of the reaction, DMF was removed and the reaction was extracted three times with methylene chloride and washed with water. After washing twice, water was removed with MgSO ₄ , and compound 2 was separated by column chromatography. Recrystallization gave a red solid compound in a yield of 44.1% (800 mg).

Wherein the NMR data and molecular weight are as follows:

¹ H NMR (300 MHz, CDCl ₃ ): δ (ppm) 7.35 (d, 9 Hz, 4H), 7.30 (t, 15 Hz, 8H), 7.14 (d, 15 Hz, 4H), 7.07 (t, 6 Hz, 4H), 7.05 (d, 9 Hz, 8H), 6.95 (d, 3 Hz, 2H), 6.93 (d, 3 Hz, 2H), 6.82 (s, 2H), 6.79 (s, 2H). ¹³ C NMR (125 MHz, CDCl ₃ ): δ (ppm) 147.6, 142.5, 135.9, 131.1, 129.5, 128.1, 127.4, 126.9, 125.1, 124.7, 124.2, 123.6, 123.3, 120.1.

Molecular weight: Calculated numerical value for C ₄₈ H ₃₆ BrN ₂ S ₂ [M] ⁺ 704.2320, HR-Mass Data: 704.2316.

Example 3 Investigation of Absorption and Luminescence Properties

The present inventors synthesize | combined the electron donor materials represented by Formula 1 (Compound No. 1) and 2 (Compound No. 2) according to the present invention according to Examples 2-1 and 2-2. In the methylene chloride solvent or in a transparent solid film, absorption and luminescence properties of Compounds 1 and 2 synthesized through the reactions of Schemes 1 and 2 were investigated, and compounds 1 and 2 and PCBM ([6,6] Absorption and emission spectra were measured in a solid film and a solution mixed with -phenyl-C61-butyric acid methyl ester in a 1: 1 ratio.

Specifically, the spectroscopic characteristics of these materials were studied through absorption (UV) and emission (PL) spectra of compounds 1 and 2. As a result, compound 1 showed main absorption at 281, 308, 441 nm in methylene chloride solvent, and compound 2 showed main absorption at 271, 386, 461 nm ( FIGS. 1 and 2 ).

In contrast, in the transparent solid film, compound 1 moved to more red regions of 280, 410, and 442 nm, and compound 2 moved to 271, 386, and 461 nm. In the case of compound 1, the emission spectrum shifted to 538 nm in methylene chloride and 565 nm in a transparent solid film, and in compound 2, 538 nm in methylene chloride and 565 nm in a transparent solid film. It was confirmed that the emission spectra of compounds 1 and 2 shifted to the red region in the transparent solid film. It is believed that this is caused by aggregation and intermolecular interaction in methylene chloride with compounds 1 and 2. In addition, in order to see the photo-induced charge separation phenomenon, when the compound 1 and the compound 2 were mixed with the PCBM in a 1: 1 ratio, the light emission at 560 nm was significantly reduced ( Fig. 4 ).

The above phenomenon is considered to be a phenomenon in which the excitons of the excitons of compounds 1 and 2 are reduced in light as electrons move to PCBM molecules by PCBM molecules. This phenomenon is a known phenomenon in the mixing system between the conductive polymer and fullerene was confirmed that occurred in a similar manner in the present invention.

Example 4 Electrochemical Analysis

Electrochemical analysis was performed to measure the electrical characteristics of the electron donor materials 1 and 2 and the energy bandgap of the material ( FIGS. 5 and 6 ). Electrochemical experiments were performed using silver and silver chloride as standard electrodes, standard hydrogen electrodes as reference, and ferrocene as reference. The sample used 0.1 M tetrabutyl ammonium hexafluoro phosphate as an additional electrode.

Experimental results showed that compounds 1 and 2 both showed electrochemically reversible oxidation and stable electrochemical stability when cationic radicals were formed. HOMO energies of compounds 1 and 2 were 5.00 eV and 5.01, respectively. eV was calculated and LUMO energy was calculated to be 2.54 eV and 2.47 eV, respectively. HOMO energy was obtained by electrochemical measurements, and LUMO energy was measured through the intersection of absorption and emission spectra.

Example 5 Thermal Stability Test

To determine thermal stability, TGA analysis of compounds 1 and 2 was performed. As a result, the T _d values of compounds 1 and 2 were measured at 412 ° C. and 431 ° C., respectively ( FIGS. 14 and 15 ). Both compounds 1 and 2 were found to be thermally stable.

Example 6 Fabrication of Organic Solar Cell Device

An anode used an ITO substrate, and was formed by spin coating a PEDOT, a conductive polymer on the substrate, to a thickness of 30 nm. Subsequently, the electron donor layer was spin-coated with compounds 1 and 2 and PCBM to a thickness of 45 nm to form an electron donor layer.

At this time, the activation layer was configured in two ways. In case of the first method, in order to see the phenomenon when there is no fullerene, the device using only the compound 1 and 2 as the electron donor layer was configured as the electron donor material. In the second method, compounds 1 and 2, which are used as electron donor layers, and PCBM, which are used as electron acceptors, are mixed at 1: 1, 1: 2, 1: 3, and 1: 4 ratios under o-dichlorobenzene solvent. A photoactivation layer was formed by spin coating.

Thereafter, BPhen (4,7-diphenyl-1,10-phenanthroline) was vacuum deposited on it to form an exciton barrier layer having a thickness of 10 nm. An organic solar cell device was manufactured by sequentially depositing 100 nm of aluminum on the electron transport layer to form an electrode. The light emitting device has a structure of several layers ( FIG. 7 ).

As a result of changing the ratio of compound 1 or compound 1 and PCBM to 1: 1, 1: 2, 1: 3, 1: 4, the device was constructed. When the compound No. 1 (hereinafter, abbreviated as 1): PCBM = 1: 1 ratio, the efficiency was 0.08%, and 1: PCBM = 1: 2 showed 0.07% of similar efficiency, 1: In the case of PCBM = 1: 3, the efficiency was increased by about 3 times and the efficiency was 0.23%. Finally, when 1: PCBM = 1: 4, the efficiency was 0.18% ( FIG. 8 ).

As a result of changing the ratio of compound 2 alone or compound 2 and PCBM to 1: 1, 1: 2, 1: 3, 1: 4, the device was constructed. When the compound No. 2 (hereinafter referred to as 2): PCBM = 1: 1 ratio, the efficiency was 0.11%, 2: PCBM = 1: 2 showed 0.07% of similar efficiency, 2: PCBM In the case of 1: 3, the efficiency was increased by about 3 times and the efficiency was 0.15%. Finally, when 2: PCBM = 1: 4, the efficiency was 0.34% ( FIG. 9 ).

The properties of devices fabricated using Compounds 1 and 2 are shown in Table 1 below.

Activation layer V _oc (V) I _sc (mA / Cm ² ) FF (%) PCE (%) 1 sole 0.018 0.00035 - - 1 : PCBM = 1: 1 0.34 0.85 27 0.08 1 : PCBM = 1: 2 0.47 0.57 27 0.07 1 : PCBM = 1: 3 0.56 1.33 30 0.23 1 : PCBM = 1: 4 0.46 1.2 31 0.18 2 sole 0.007 0.000086 - - 2 : PCBM = 1: 1 0.52 0.75 27 0.11 2 : PCBM = 1: 2 0.34 0.79 26 0.07 2 : PCBM = 1: 3 0.45 1.22 27 0.15 2 : PCBM = 1: 4 0.51 1.88 34 0.34

Example 7 AFM Characterization

The device was constructed using the above compounds 1 and 2, in a device using 1: PCBM = 1: 1, 1: PCBM = 1: 3 and 2: PCBM = 1: 1, 2: PCBM = 1: 4 To determine why the two devices differ, AFM (atomic force microscopy) photographs were taken to analyze the shape of the film surface.

The results of atomic force microscopy show that the difference in efficiency in the case of 1: PCBM = 1: 1 and 1: PCBM = 1: 3 results in the formation of holes or aggregated surfaces when 1: PCBM = 1: 1. On the contrary, in the case of 1: PCBM = 1: 3, the surface of the film was clean and it could not be confirmed that it was formed by agglomeration or holes. Through the atomic force microscope as described above it was confirmed that the difference in efficiency about three times ( Figs. 10 and 11 ).

On the other hand, when 2: PCBM = 1: 1, many holes or agglomerated surfaces were shown. On the contrary, when 2: PCBM = 1: 4, the surface of the film was clean and it could not be confirmed that it was formed by agglomeration or holes. Similarly, the atomic force microscopy as described above was able to confirm the reason for the difference in efficiency about 3 times ( FIGS. 12 and 13 ).

As a result, the atomic force microscopy showed that compounds 1 and 2 exhibited a similar pattern.

FIG. 1 shows UV-abs (Ultraviolet absorption) and PL (photoluminescence) spectra in methylene chloride solvents of compounds represented by Compounds 1 and 2 synthesized in Examples 2-1 and 2-2,

2 is a UV (absorption) and PL (luminescence) spectrum in a transparent solid film of the compound represented by Compounds 1 and 2,

3 is an absorption spectrum in a transparent solid film when compound 1 or 2 alone or 1 or 2 and PCBM are mixed 1: 1;

4 is an emission spectrum in a transparent solid film when compound 1 or 2 or 1 or 2 and PCBM are mixed 1: 1.

5 is an electrochemical spectrum of compound 1 in a methylene chloride solvent,

6 is an electrochemical spectrum of compound 2 in methylene chloride solvent,

7 is a structure of an organic solar cell device according to the present invention,

<Description of the symbols for the main parts of the drawings>

10 ... anode electrode 20 ... conductive polymer

30 ... electron donor layer 40 ... electron acceptor layer

50 ... exciton barrier layer 60 ... cathode electrode

FIG. 8 is a graph showing the composition of the compound No. 1 and PCBM in a ratio of 1: 1 to 1: 4 and mixed in various ratios,

FIG. 9 is a graph showing the composition of the compound No. 2 and PCBM in a ratio of 1: 1 to 1: 4, mixed at various ratios,

10 is an AFM photograph of a device composed of a No. 1 compound and a PCBM in a 1: 1 ratio.

FIG. 11 is an AFM photograph of a device obtained by mixing compound No. 1 and PCBM in a 1: 3 ratio.

12 is an AFM photograph of a device composed of No. 2 compound and PCBM in a 1: 1 ratio.

FIG. 13 is an AFM photograph of a device obtained by mixing compound No. 2 and PCBM in a 1: 4 ratio.

14 is a data obtained by TGA analysis of compound 1.

15 is a data obtained by TGA analysis of compound 2.

Claims (12)

A compound of formula 1 (2,5-bis [4- (N, N-diphenylamino) styryl] thiophene) serving as an electron donor material of an organic solar cell. <Formula 1>

A compound of formula 2 (2,5-bis [4- (N, N-diphenylamino) styryl] -2,2-bithiophene), which acts as an electron donor material of an organic solar cell. <Formula 2>

The above-mentioned claim 1, which acts as an electron donor by reacting 2,5-dibromothiophene or 5,5'-dibromo-2,2'-bithiophene, Biphenyl- (4-vinylphenyl) amine, Palladium acetate, tetrabutylammonium bromide, and NaOAC. A process for preparing the compound of claim 2. The method according to claim 3, wherein the production method is prepared by the reaction of Scheme 1 or Scheme 2 below. <Scheme 1>

<Scheme 2>

A thiophene derivative (thiophene) having a high hole transfer speed is the center, and a compound conjugated with two or more triphenylamine derivatives outside the thiophene derivative is used as an electron donor material. Organic solar cell made. 6. The organic solar cell of claim 5, wherein the compound is thermally stable and spin coatable. The organic solar cell of claim 5, wherein the number of thiophene derivatives is 1 to 5. The organic solar cell of claim 5, wherein the electron donor material is mixed with a PCBM ([6,6] -phenyl-C61-butyric acid methyl ester) which acts as an electron acceptor. The organic solar cell of claim 8, wherein the PCBM is contained in an amount of 1 to 4 by weight of the electron donor material. The organic solar cell according to any one of claims 5 to 9, wherein the combined compound of the triphenylamine derivative and the thiophene derivative is Formula 1 or Formula 2. The method of manufacturing the organic solar cell of claim 5, wherein the PCBM acting as an electron acceptor on the electron donor material of claim 1 or 2 is spin coated. The method of claim 11, wherein the chemical formula 1 or 2 and PCBM is a weight ratio of 1: 1 to 1: 4.

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